The present invention concerns a transport container, preferably made of plastic material, especially for vegetables and fruit in accordance with the descriptive part of Claim 1 or 9.
Collapsible transport containers made preferably of plastic materials are used for many different transport purposes, because they are not only very stable, but also very light and, given the fact that they can be folded, occupy very little space when they have to be transported in the empty state. Particularly the lightness of such transport containers is further enhanced by the fact that the provision of numerous strengthening ribs makes it possible to save a great deal of material. But this is associated with the drawback that especially the outside of the transport containers becomes very uneven and has numerous edges and recesses. Apart from dirt collection problems, this gives rise to such further problems that, especially in the area of the floorboard and when the transport containers are used to carry fruit, bananas for example, and have to be stacked on top of each other, any fruit projecting slightly above the upper edge of the lower container is liable to be damaged by the edges and strengthening ribs of the upper container.
Another disadvantageous feature of known collapsible transport containers derives from the fact that their sidewalls, which are secured to each other in the upright position by means of fastening elements, may already collapse when pressure acts on them. Although this is helpful for the purposes of quick and simple handling, it also has the disadvantage that, given inexpert handling, which the containers will often suffer in practice when they are in frequent use, the side walls will not be properly fastened in their upright position, which can lead to a collapse of the side wall during loading and stacking and consequent damage of the merchandise contained therein. Moreover, the currently used fastening and securing elements are often difficult to operate and not easy to locate on the containers. Often there is also the further problem that improper use may cause damage to the fastening and securing elements.
It is therefore the scope of the present invention to make available a collapsible transport container that will not be sensitive to excessive and improper use as may occur, for example, when the transport containers are overloaded and their side walls become subject to considerable and bumpy loads. In particular, the invention seeks to create a transport container that has as smooth as possible an underside and is devoid ribs and reinforcing stays, thereby avoiding the possibility of the merchandise in an underlying container becoming damaged due to these strengthening ribs being pressed into it. Nevertheless, the container floor should also be sufficiently stable to assure safe transport of the goods carried in the container. A further task of the present invention is to create a means of fastening the collapsible side walls to each other when in the upright position, where the said means is to be easy to operate, i.e. easy to open and close, and not sensitive to pressure or impact loads. In particular, ready handling is to be assured by enabling the user to open and close these fastening elements without having to change either his own position or that of the transport container.
This task is absolved by a transport container having the characteristics of Claims 1 and 9. Advantageous embodiments are set out in the dependent claims.
The transport container in accordance with the invention has an essentially rectangular floorboard that consists of a frame and a floor profile arranged in it. Attached to the frame there are collapsible side walls, preferably four in number, that can be swivelled between a folded position, in which they lie on the floorboard, and an upright position, in which they project upward from the floorboard and substantially make a right angle with it. The floor profile has a smooth upper and lower surface, both of which are wholly devoid of strengthening ribs or stays, and owes its stability to several bulges provided in the floor profile, the said bulges being obtained by curving the floor profile in several space directions. This results in a three-dimensional floor profile that the said bulges render adequately rigid and which, given the consequential possibility of avoiding the use of strengthening ribs, also has a smooth surface that is easy to keep clean and will not damage the underlying merchandise when the transport containers are stacked on top of each other, because the lack of strengthening ribs assures that no peak loads can occur in this area when it comes into contact with the underlying merchandise, and that there will rather be a uniformly distributed load.
Preferably the three-dimensional form of the floor profile is obtained by bending the floor profile upward in the manner of an arch along its shorter side and giving it a wavelike form along the longer side. A structure of this type will not only assure a particularly good rigidity, but will also bring with it a number of technical advantages in the production process.
Advantageously the bulges in the floor profile will be provided in such a manner that there will be horizontal floor sections between these bulges. This has the advantage that there will be at least some horizontal surfaces on which the merchandise to be carried in the transport container can bear. Over and above this, the presence of these horizontal floor sections assures that there will be areas where the floor profile can be attached to the surrounding frame in a very simple manner.
Correspondingly, in the presence of a stacking shoulder, which should preferably be provided on the floorboard, so that in a stack of transport containers it can engage (interlock) with the container lying beneath it, it will be advantageous to provide stacking grooves to permit staggered stacking of the transport containers, locating these grooves in the areas in which the horizontal sections of the floor profile border on the stacking shoulder or the frame of the floorboard. In this way one obtains a smooth transition from the floor profile to the frame of the floorboard in these areas.
In the case of a floorboard with a stacking shoulder it will also be advantageous to provide the bulges as depressions in the floor profile in such a manner that they will come to extend in the area between the upper end of the stacking shoulder and the lower end of the stacking shoulder. From the manufacturing point of view this offers the advantage that, starting from the horizontal floor sections, which can be attached to the upper end of the stacking shoulder, the outer border of the floor profile can always be attached to the stacking shoulder, i.e. when there are depressions along these borders right down to the lower end of the stacking shoulder.
Preferably the floor profile will be formed as a single piece with the frame, which can be done, for example, when the floorboard is made from plastic materials by means of injection moulding.
With a view to further enhancing the rigidity of the floor profile, it can be held in the frame in such a manner as to become subject to a prestressing force and, more particularly, in such a manner that the bulge (upward in the manner of an arch, for example) will become more pronounced due to the elastic stresses. In this way the carrying capacity of the floor profile can be further enhanced.
In accordance with a second aspect of the invention the collapsible transport container is provided with a device to keep the collapsible side walls secured to each other in their upright position, the said device consisting of a fastening mechanism on adjacent side walls. The said fastening mechanism comprises a fastener with a fastening bolt that is provided on one of the side walls, together with a recess in the adjacent side wall with which the fastening bolt can engage. The fastener consists of an element that can be displaced against the force of an elastic spring element, where the said displaceable element comprises or operates the fastening bolt and is substantially accommodated within the side wall. Given this accommodation of the fastener within a side wall, the fastener is advantageously protected against being damaged by forces that act on it from outside. Furthermore, the fact that the displaceable element is pre-tensioned by an elastic element or by the force that is needed to displace the displaceable element assures that an unintentional operation of the fastening mechanism due to the action of a pure pressure or force on the side wall can be excluded.
Advantageously the displaceable element will be arranged within the side wall in such a manner as to permit its being operated both from the outside of the side wall and from the inside. In particular, this can be obtained by inserting the displaceable element and therefore the fastener in a fastener cutout in the side wall in such a manner that the fastener can be operated from both sides of the side wall through gripping troughs arranged on both sides of the displaceable element or a gripping opening that extends right through it. The fact that the fastener can be operated from both sides has the advantage that all the side walls can be collapsed without either the operator having to change his position or the transport container having to be rotated.
From the point of view of manufacturing technique, moreover, the fact that the fastener can be inserted in a cutout provided in a side wall has the advantage that the fastener can be made as a single piece from plastic materials and then be simply clipped into the cutout in the side wall.
The fastener is preferably held and/or guided in the cutout in the side wall by means of notch elements constituted by projections, stays or the like. Since the displaceable element of the fastener in the side wall has to be displaced to operate the fastening bolt, the cutout opening must be sufficiently large to permit this displacement of the displaceable element. In order to assure that in a given position the fastening bolt and/or the displaceable element associated with it will be appropriately pre-tensioned by the elastic spring element, the displaceable element is arranged in the side wall in such a manner as to be connected to the side wall via the elastic element.
This can preferably be done by means of a holder plate that forms part of the fastener and is firmly attached to the side wall. Alternatively, however, the elastic element can also be attached directly to the side wall.
Since the displaceable element is linked to the side wall via the elastic element, the displaceable element is maintained in the position in which the elastic spring element is slack. This is preferably the fastened position, namely the one in which the fastening bolt is engaged with the recess in the adjacent side wall. This presetting in the fastened position effectively avoids an unintentional collapse of the transport container.
In a preferred embodiment of the fastener an essentially rectangular frame body acts as the displaceable element that at one of its ends is provided with either circular gripping troughs on both sides or a gripping opening that extends right through the element. The width of the frame body or displaceable element matches the thickness of the side wall, so that the fastener is essentially flush with the inside and/or the outside of the side wall. Within the frame body there is preferably arranged the elastic element, which is essentially and advantageously designed as an S-shaped spring and has one of its ends fixed to the side of the frame body opposite to the gripping trough and its other end fixed laterally either directly to the side wall or to holder plate of the fastener, this plate being preferably situated within the fastener cutout as a continuation of the side wall. This embodiment occupies particularly little space and also assures adequate protection of the spring element by the surrounding frame body. The S-shaped design of the spring assures a particularly long spring excursion that does not call for the application of any great force.
In a preferred embodiment the fastening bolt is arranged directly on the displaceable element on the side of the frame body opposite to the gripping trough or the gripping opening, so that the displacement of the displaceable element will also cause the displacement of the fastening bolt.
When the fastener is to be opened, i.e. when the adjacent side walls are to be detached from each other, the operator, inserting his hand in the gripping trough or the gripping opening, must displace the displaceable element against the spring force of the elastic element, so that the fastening bolt will become disengaged from the recess in the adjacent side wall. Since preferably the displaceable element is provided with a gripping trough on both sides or a gripping opening that passes right through the displaceable element, the holder plate, which is preferably arranged parallel to the surface of the side wall and the displacement path of the displaceable element, will extend only over a part area of the displaceable element, preferably about two thirds and will not therefore cover the area of the gripping trough or the gripping opening.